Migration to 4.0.0

[xnerhu]

This is a guide for migrating to v4.0.0. This version introduces a lot of breaking changes since v2.6.0.

Documentation:

• v4.x.y
• v2.6.0

Breaking changes

Client

Client.abort()

• Now aborts all tasks.
• To abort a transfer use Client.abortTransfer().

Client.connect(config, options)

• Changed options - IOptions => IOptions | FtpOptions | ISftpOptions.

Client.connected

• Removed.

Client.createBlank()

• Removed.

Client.delete()

• Removed, because in some protocols, there is no way to check if path is a folder or a file.

`Client.download(remotePath, dest, options)

• Switched the order of dest and remotePath arguments.
• Changed options to startAt (number).

Client.isSftp

• Removed.

Client.mkdir()

• Changed to Client.createFolder.

Client.protocol

• Removed. You can access this by Client.config.protocol.

Client.readDir()

• Changed to Client.list.

Client.rimraf()

• Changed to Client.removeFolder.

Client.stat()

• Removed.

Client.touch()

• Changed to Client.createEmptyFile.

Client.unlink()

• Changed to Client.removeFile.

`Client.upload(remotePath, source, options)

• Switched the order of source and remotePath arguments.
• Removed options argument.

Event connected

• Changed to connect.

Event disconnected

• Changed to disconnect. Emitted everytime a connection is closed.

Event abort

• Changed to transfer-abort. Emitted everytime some transfers are aborted.

Event progress

• Changed to transfer-progress. See listener options.

ConcurrentClient

• Removed.
• You can set a pool of connections by providing options to Client.constructor.

Interface IConfig

• Because of the ability to register custom protocols, this interface consists only of generic options. If you want to use interface
  for ftp protocols, check this.